This invention relates in general to the recovery of energy from below the earth's surface and more particularly to improvements to such energy recovery systems.
In recent years, commercial utilization of geothermal energy has acquired greater status and interest because of the long-range dwindling of fossil fuel sources of energy and tragic experiences with nuclear power plants.
Presently available technology associated with geothermal energy recovery, is primarily directed to the extraction of heat from readily available natural resources located within the earth's crust and readily exposed by the drilling of relatively shallow wells. Such geothermal energy recovery systems are disclosed for example in U.S. Pat. Nos. 2,461,449, 3,274,769, 4,052,857, 4,094,356, 4,201,060, 4,512,156, 4,642,987 and 4,644,750. The readily available geothermal resources to which such prior art technology is adaptable, includes for example hot artesian wells and similar naturally occurring sources of vented steam or super heated water as referred to in U.S. Patent No. 3,274,769 to Reynolds. Other naturally occurring and readily available geothermal sources include salt formations as referred to in U.S. Pat. No. 4,052,857 to Altschuler. The latter types of naturally occurring geothermal sources of energy located within the earth's crust layer, are not available in all locales for which reason utilization of geothermal energy fro such sources has been limited.
Geothermal energy is, of course, available at greater depths below the earth's surface, such as the mantle layer. However, the tapping of geothermal energy from such ultra-deep depths within the earth's mantle or zones approaching the magma have not been seriously considered heretofore because of expected heat losses in extracting energy from such depths. It will, however, be apparent that the extraction of geothermal energy from ultra-deep wells extending to the earth's mantle, will not be limited to restricted locales. By reason thereof, the provision of an economically efficient geothermal energy recovery system adaptable for ultra-deep wells offers the advantage of utilizing existing above-surface electrical power generating equipment and installations so as to avoid the relocation and construction of new generating plants adjacent to restricted locales.
It is therefore an important feature of the present invention to provide a method and apparatus for enhancing geothermal energy recovery to such an extent so as to avoid the restricted locale limitations heretofore associated with prior art geothermal recovery systems.
It is an additional feature of the present invention to provide a geothermal energy recovery system which may be utilized with existing electric power generating installations so as to avoid relocation and construction of new generating plants near or adjacent to naturally occurring geothermal resources.
Another feature of the present invention is to provide an economical and easily fabricated apparatus which may be installed in new or existing wells suitable for geothermal energy recovery.
Still another feature of the present invention is to provide a method and apparatus which can be easily manufactured and installed yet efficiently recover geothermal energy from the earth's crust.